Organic Light-Emitting Diode (OLED) has the advantages of simple fabrication process, low cost, capable of adjusting color of the emitted light in the visible region, easy for mass production, good flexibility and the like, and thus an OLED display device using the OLED is regarded as one of the most promising display technologies in the future. White OLED (WOLED) has a power efficiency over 60 lm/W and a lifetime of 20,000 hours or more, which greatly promotes the development of the WOLED display device.
The OLED display device comprises a plurality of pixel units, and each pixel unit comprises an OLED and a thin film transistor for driving the OLED. However, the light emitted from the OLED may adversely affect the characteristics of the thin-film transistor (e.g., an oxide thin-film transistor), resulting a deterioration of the display effect of the OLED display device. FIG. 1 is a diagram showing the relationship between the wavelengths of a red light, a green light, a blue light and a mixed light (c light) mixed by the red, green and blue light and the transmittance. It is found that the light with a shorter wavelength (e.g., the blue light, especially the blue light with a wavelength of 400 nm or less) among the light emitted from WOLED has a greater impact on the characteristics of the thin-film transistor (e.g., an oxide thin-film transistor), a leakage current is generated due to the light irradiation, and thus the display effect is deteriorated. Therefore, it is especially necessary to avoid the adverse impact of the light with shorter wavelength on the thin-film transistor.